Version 4.10.0: Added MapProjections library project.

MapProjections/Shared/GeoApiProjection.cs

@@ -0,0 +1,92 @@
+// XAML Map Control - https://github.com/ClemensFischer/XAML-Map-Control
+// © 2018 Clemens Fischer
+// Licensed under the Microsoft Public License (Ms-PL)
+
+using System;
+using System.Text;
+#if !WINDOWS_UWP
+using System.Windows;
+#endif
+using GeoAPI.CoordinateSystems;
+using GeoAPI.CoordinateSystems.Transformations;
+using ProjNet.Converters.WellKnownText;
+using ProjNet.CoordinateSystems;
+using ProjNet.CoordinateSystems.Transformations;
+
+namespace MapControl.Projections
+{
+    /// <summary>
+    /// MapProjection based on ProjNET4GeoApi.
+    /// </summary>
+    public class GeoApiProjection : MapProjection
+    {
+        private ICoordinateTransformation coordinateTransform;
+        private IMathTransform mathTransform;
+        private IMathTransform inverseTransform;
+        private string wkt;
+
+        /// <summary>
+        /// Gets or sets the underlying ICoordinateTransformation instance.
+        /// Setting this property updates the CrsId property.
+        /// </summary>
+        public ICoordinateTransformation CoordinateTransform
+        {
+            get { return coordinateTransform; }
+            set
+            {
+                coordinateTransform = value;
+                mathTransform = coordinateTransform.MathTransform;
+                inverseTransform = mathTransform.Inverse();
+
+                if (coordinateTransform.TargetCS != null &&
+                    !string.IsNullOrEmpty(coordinateTransform.TargetCS.Authority) &&
+                    coordinateTransform.TargetCS.AuthorityCode > 0)
+                {
+                    CrsId = string.Format("{0}:{1}", coordinateTransform.TargetCS.Authority, coordinateTransform.TargetCS.AuthorityCode);
+                }
+            }
+        }
+
+        /// <summary>
+        /// Get or sets an OGC Well-known text representation of a projected coordinate system,
+        /// e.g. a PROJCS[...] string as used by https://epsg.io or http://spatialreference.org.
+        /// Setting this property updates the CoordinateTransform property.
+        /// </summary>
+        public string Wkt
+        {
+            get { return wkt; }
+            set
+            {
+                var sourceCs = GeographicCoordinateSystem.WGS84;
+                var targetCs = (ICoordinateSystem)CoordinateSystemWktReader.Parse(value, Encoding.UTF8);
+
+                CoordinateTransform = new CoordinateTransformationFactory().CreateFromCoordinateSystems(sourceCs, targetCs);
+                wkt = value;
+            }
+        }
+
+        public override Point LocationToPoint(Location location)
+        {
+            if (mathTransform == null)
+            {
+                throw new InvalidOperationException("The Wkt property is not set or not valid.");
+            }
+
+            var xy = mathTransform.Transform(new double[] { location.Longitude, location.Latitude });
+
+            return new Point(xy[0], xy[1]);
+        }
+
+        public override Location PointToLocation(Point point)
+        {
+            if (inverseTransform == null)
+            {
+                throw new InvalidOperationException("The Wkt property is not set or not valid.");
+            }
+
+            var lonLat = inverseTransform.Transform(new double[] { point.X, point.Y });
+
+            return new Location(lonLat[1], lonLat[0]);
+        }
+    }
+}